多重耐药鲍曼不动杆菌的耐药性与AmpC耐药基因的研究

目的了解我院临床分离的60株多重耐药鲍曼不动杆菌（multi-drug resistant Acinetobater baumannii,MDRAB）的耐药性和AmpC耐药基因的存在状况。方法采用VITEK-2全自动细菌鉴定仪检测鲍曼不动杆菌对18种抗生素的药敏结果,对该细菌进行总DNA的提取,用聚合酶链反应（PCR）检测耐药基因,结合药物敏感试验分析菌株的耐药特征。结果检出结构基因ampC型49株,占81.7%;blaADC基因型50株,占83%;ACT基因型2株;41株菌同时携带blaADC和ampC结构基因,占68%;2株同时携带blaADC、ACT和ampC结构基因;未检测到其它AmpC耐药基因（MOX、CIT、FOX、DHA）。携带AmpC耐药基因的菌株耐药率高,特别是对头孢曲松、氨苄西林、头孢替坦、头孢唑啉、呋喃妥因的耐药率已接近或达到100%,而对于丁胺卡那霉素和头孢哌酮/舒巴坦的耐药率最低,分别为5%和20%。结论多重耐药鲍曼不动杆菌的blaADC耐药基因和ampC结构基因同时携带率高,并且是鲍曼不动杆菌多重耐药的主要原因。

Study on the Antibiotic Resistance and AmpC Gene of Multi-drug Resistant Acinetobater baumannii

Objective To investigate the antibiotic resistance and AmpC gene in 60 strains of multi-drug resistant Acinetobater baumannii（MDRAB） isolated from the first affiliated hospital of Guangzhou Medical College.Methods Resistant features to 18 kinds antibiotics were analyzed by Vitek-2 Compact.DNA was extracted from 60 strains of MDRAB for the analysis of drug resistant gene by PCR.The data was combined with the drug sensitivity test to evaluate the antimicrobial resistance characteristics.Results The results showed that the positive rate of ampC gene was 81.7%（49 /60）and blaADC gene was 83%（50 /60）.2 strains carried blaACT gene.The ampC and blaADC gene were both positive in 41 strains.2 strains carried blaACT,ampC and blaADC genes at the same time.MOX,CIT,FOX and DHA genes were negative in all strains.The strains of carrying AmpC gene have a high resistance rate,especially for the Ceftriaxone,Ampicillin,Aefotetan,Cefazolin and Nitrofurantoin was approach or reach 100%,but for Amikacin and cefoperazone-sulbactam had the lowest resistance rate,with the detection ratio of 5% and 20%,respectively.Conclusions There were very high positive percentages of ampC and blaADC gene present at the same time in MDRAB.It could be the main reason that caused Acinetobacter baumannii multi-drug resistant.